Cell culture is the process of growing living cells under controlled laboratory conditions, typically outside their natural environment. The technique provides a defined environment where cells from multicellular organisms or unicellular microbes can proliferate on nutrient media in incubators.
Explanation
In cell culture, cells are supplied with a sterile growth medium containing essential nutrients, growth factors, buffering salts and sometimes serum. The culture vessel is maintained at an appropriate temperature, pH and gas composition (often 5% CO₂ for mammalian cells). There are two major categories: primary cultures, which are established directly from tissues and have a limited lifespan, and cell lines, which have adapted to grow indefinitely. Mammalian cell culture is indispensable for studying cell biology, cancer and immunology and for producing recombinant proteins and vaccines. Many viruses, including influenza and poliovirus, require living cells for replication; they are propagated by infecting susceptible cell lines and monitoring cytopathic effects. Bacterial and yeast cultures, although also referred to as cell culture, are typically grown in liquid broth or on agar plates and can be scaled up for industrial fermentation. Maintaining cultures free of contamination from other microorganisms is critical; aseptic technique, antibiotics and laminar flow hoods are used to minimise contamination. Subculturing, or passaging, refers to splitting cells into new vessels to prevent overgrowth and maintain exponential growth.
Applications and Examples
Cell culture supports biotechnology and medicine. HeLa (human cervical cancer) and Vero (African green monkey kidney) cell lines are widely used for virology and toxicology studies. Chinese hamster ovary (CHO) cells are a workhorse for biopharmaceutical production of monoclonal antibodies and hormones. Primary neuronal cultures allow researchers to investigate synaptic plasticity and neurodegenerative disease mechanisms. Vaccine production for rabies, measles and COVID‑19 often involves growing attenuated viruses or viral vectors in mammalian cells. In addition, tissue culture techniques enable cloning of plants and propagation of stem cells for regenerative medicine.
By providing a controlled environment to study living cells, cell culture has revolutionised microbiology, virology and biotechnology.
Related Terms: tissue culture, cell line, medium, sterile technique, incubator